The Messenger of Allah ﷺ said, "Do not perform continuous fasting."They said, "Messenger of Allah, but you yourself fast continuously."He replied, "I am not like you. I spend the night with my Lord feeding me and giving me drink."Yet they did not refrain from continuous fasting, so the Prophet ﷺ fasted continuously with them for two days and two nights. Then they sighted the new moon, and the Prophet ﷺ said, "Had the new moon been delayed, I would have continued with you longer," as if disciplining them.
حدثنا عبد الرزاق حدثنا معمر عن الزهري عن أبي سلمة
قال رسول الله ﷺ لا تواصلوا قالوا يا رسول الله إنك تواصل قال إني لست مثلكم إني أبيت يطعمني ربي ويسقيني قال فلم ينتهوا عن الوصال فواصل بهم النبي ﷺ يومين وليلتين ثم رأوا الهلال فقال النبي ﷺ لو تأخر الهلال لزدتكم كالمنكل بهم
Its isnad is sahih. Bukhari related it in 13:234 by way of Mamar, from Zuhri, with this isnad, in similar wording. He also related it in 4:179 slightly more fully, from the narration of Shuayb, from Zuhri. Muslim related it in 1:303-304 by way of Yunus, from Zuhri, at greater length. The prohibition of wisal has already been mentioned several times, most recently at 7539.